Rod clamp



Feb. 14, 1928.

R. A. LETT ROD CLAMP Filed Nov'. 29. 1924 30 fragment;

Patented Feb.14,192a. l l 1,659,111

UNITED STATES PATENT oFFlcE.

ROYAL A; LETT, MIAMI, FLORIDA, ASSIGNOR, BY vDIRECT AND MESNE ASSIGN- MENTS, OF ONE-HALF TO ROBERTV E.IIALL, M1IAMIFLOBIDA, AND ONE-THIRD TO GEORGE N. MURLDOCK, OF CHICAGO, ILLINOIS. 4

Y non CLAMP. Appneano med November 29, 1924. s"rifiv il` 752,999.4

This invention relates to certa-in new and terminals extendedflaterally to `one side, as

useful kimprovements in a rod clamp, and at (Sand 7, on the opposite sides fof a standmore particularly to a device of this genard 8j rising from theU-body'Q substantially 55 eral type especially adapted for easement mid-way betweenthe guides and to one side 5 window adjusters', vtransom a'djusters, and,` thereof. A lever 10 fis fulcrumed on this 1 the like, the primary object being to 1`or1ovideV standard 'between its ends,1byfa1y pivoting v an exceedingly simple :construction which screwfll,fand'has a seat 12' formed in they f will firmly and positively grip the rod and rupper" edgejon one side of' the pivot 111 to 60 which may readily be released therefrom by constitute a bearing for the terminal 6 of l0 a simpl@ Operation; Y, 1 thespring, and'on the opposite-side of said The invention resides broadly, in a coiled, pivot 11 the lever is provided with a seat resilient or yieldable member constricted 13 in the loweredge to form a bearing for normally aboutthe adjuster rod and having the spring terminal 7. Obviously, the de- 65 means for imparting relative spreading pression ofthe lever from the position yde- 15 'movement of the opposite end portions/0f pictedlini Figure 4 will effect a spreading the member fin a circumferential, unwinding of the terminals 6 and 7 and a partial un- 1 direction. n 1 winding ofthe spring. The latter, normal- The inventiony further resides in the ly, closely embraces the rod 4 and friction- 70 mounting of the clampingy device for adally grips the same, `positivelyholding the justment, and means for securing the same rod against longitudinal movement. The Xed on its mounting. V operation ofthe lever effects a release of the Further, the invent-'on is found to'reside rod by the slight unwinding accorded in in the salient features of construction, yand `1 spreading the terminals 64 and 17. 1 15 the arrangements and combinations ofparts' A casing114 incloses the clamping struc- 25, hereinafter describedV and claimed, reference ture, being resting freely on the plate 1 so as being madel to the accompanying drawing, y1to1 rotate oroscillate with the rod and the wherein 1 body 9, saidk casing having its cylindrical Figure 1 is a plan viewv of the clamp in wall apertured to receivetherod 4 land ver` s0 1 position on a rod, the latter being shown in tically slitted, as at, 15, toreceive the eX- tended end ofthe lever,tlie latter terminat- Figure 2 is aside elevation of thesamejing in 'asuitable buttonor handle 16. The

Figure 3 is a top plan view, similarto cover 17 of the casing is secured' to the base that of Figure 1', with the cap or cover plate yby, the screws 118 passing throughthe ears `85 removed; l 1 Y 19,'.a1id is therebyheld against rotation,1the Figure 4 is a vertical section on lineV4-4 cylindrical wall rotating freely between the v:of Figure 1; ,jl "base plate 1 and thecover y17. 1'

Figure 5 is a similar view on line 51-5 They constructionofthe coiledclamping of Figure l3; v member is particularly important, theI con- 90 Figure 6 is a sectionalview on `line 6-6 volutions or coils beingwoundclose together of lFigure 4; 1. I 1 y so thatthere will be no longitudinal play Figure 7 vis a modified showing. between them. YV,In practice, the spring is in- Referring more in detail to the accomitially wound on a mandrel of smaller diampanying drawing, the. numeral 1 designates eter than the rody to which it isto be applied 95 a base or mounting plate, which may be of so that when itis applied to 11the`rod its coils `a desired shapedepending yupon the use to will closelyy hug or grip the same under norwhich the clamp is to be applied. Secured 1 mal,v conditions. The length of the coiled upon this mounting 1, as by a pivoting rivet spring is substantially equal to the .spacebe- 2, is a preferably U-shaped body providing tweenthe guides 3 to prevent longitudinal 100 upstanding, spaced members Biwliich are apmovementy of the spring between the sanie. ertured to slidably receive and guide `the ad- The actionfof the lever on ,they spring is juster rod 4. Confined between the spaced to effect al partial unwinding of they' coils guides 3 is a coiled Spring 5 which has its suiiicientto release thegrip of the sameon thel rod and to this end it is desirable to have the coils at the center function as nearly simultaneouslykwith the opening of the end coils whereby the rod will be released and gripped more uniformly and effectively. In carrying this into practice, and referring to LFigure 5, I initially wind the spring with a slightly contracted center, or, .in other words, the coils are gradually reduced in diameter from the opposite ends so that the central coils or convolutions are ot reduced diameter as compared with the end coils. Following this Winding, Ipass a broaching tool through the coiled spring to produce a substantially true, cylindrical, interior surface, which operation cutsl oli' varying arcs :troni the inner peripheries of the ycoils toward the center, producing flattened faces, as is depicted .on an exaggerated scale at 2O in said Figure 5. In practicei,this reduction of the inner coils will not exceed several thousandths ot an inch, and yet the slight reduction is sulicient to weaken the coils gradually or progressively toward the center or from opposite ends. By thus gradually weakening the coils inwardly, the inner coils will expand more evenly and simultaneously with the stronger, outer Vor end coils.

It it is desired to secure the clamp body 9 against rotation on the base plate l, the same may be accomplished by providing an apertured ear 2l on said body and mounting a. vertical pin 22 in the aperture thereo'l with an encircling spring 23k arranged to urge the pin upwar'dlyinto contact with the lower edge of the lever. Therefore, upon depressing the lever end, by releasing on the handle or button 16, the pin 22 downwardly into engagement with the selected one of an arcuate series or catches or seats 24 formed on the plate l. When the lever is depressed to release the clamp, the locking pin will be automatically withdrawn by its spring 23.

In Figure 7, the reverse idea is expressed, the clamping spring 25 being normally free of the rod and the action of the lever 26 is to spread the spring terminals circumfereir tially ina windingl direction whereby the spring coils will be tightened into gripping relation with the rod. i

The improved form of clamp is particularly useful where a rod or link is to be eX- tended and secured in adjusted positions, such as casement adjustment, transom lifters, brake rods, and similar e spring clamp is very effective in holding the rod against lengthwise movement and yet permits rotation of the rod.

Obviously, various changes in the construction and arrangement of the improvements may be resorted to, as

Y fall within the scope of the appended claims and Without departing -from the spirit of the invention.

is projected V`What is claimed is:

l. In a device of the class described, a rod, a clamp therefor embodying a coiled spring designed to snugly embrace the rod under normal conditions, and means for simultaneously spreading Ythe opposite ends of the spring to e'liect a partial unwinding of the latter. Y

In combination with a rod, of a coiled spring liictionally embracing the saine, means for holding the spring against movenient with the rod, and means for loosening the grip of the spring upon the rod by an unwinding action oit its coils.

3. In combination, a Vr d, a coiled spring clan'ipingly enbracing the rod and having its terminals extended laterally in substantially parallelism, and a lever pivoted between the terminals for engaging, Vthe saine to spread the same circumiterentially in an unwinding direction.

i. In combination with a rod, a body through which the rod is guided, and a spring within the body encircling the rod in normal trictional contact with the' latter and adapted to have its ends relatively spread apart to release the coils of the spring` trom the rod.

5. In combination with a rod, a body having spaced guides therefor, a spring conlined between the guides and coiled about the rod in normal frictional contact there-y with, and means for releasing the i'od from the normal gripping contact with the spring.

6. A body having a stop, a' rod-encircling spring engaged with the stop against axial movement, and means for exerting a circumferential movement to one terminal of the spring relative to the opposite terminal to etliect a variation in the size of the coils of said spring.

'l'. A body having' spaced rod guides apertured to receive and guide a rod, a. closely wound coiledr spring interposedbetween the guides, and means carried by the body for relatively spreading the ends of the spring circumferentially to enlarge the size oi the coils thereof.

8. In combination with a rod to be clamped, a coiled spring encircling the same, and means tor imparting relative circumferential movement to the terminals of the spring, the intermediate coils ot the spring being weaker than the end coils.

9. In combination with a rod to be clamped, a coiled spring encircling the same, and means for imparting relative circumferential movenient to the terminals 0f the spring, said spring having its inner coils contracted relative to the outer coils and their inner peripheries enlarged to substantially the diameter of the outer coils.

IO. In 'a rod clamping device, a base, a body pivoted thereon, means for holding the body against pivotal movement, means for the body, and a common clamping a rod to for rendering the two operating device means inoperative.

1l. In a rod clamping device, a pivotally mounted body having rod guides, means ybetween the guides for clamping a rod, means for holding the body against pivotal movement, and a common control for the first and second means. y

12. In a rod clamping device, a bodyr having spaced rod guides, a coiled spring litting between the guides and held thereby against longitudinal movement, vand means ment to the terminals of the spring. e

13. A spring tor a rod clamping device, comprising a coiled body formed of a `plurality of connected coils, one portion of said body being formed to receive a torsional torce and the adjacent portion of saidcoiled body having its individual coils progressively weaker away from that portion to which the torsional force is to be applied.

for imparting relative circumferential move- 14. A rod clamp com rising a coiled spring body designed for iaving a normal Jrictional embrace With a rod, a member e11- gaged by the spring body for being connected by the latter to an embraced rod, and means for exerting an unwinding force on one terminal ot the springr'body to enlarge the nonmal diameter of the spring body and thereby exert a release kor' the normal gripping relation which said spring body will have with an embraced rod.

15. A rod clamp comprising a coiled spring body tor normally and frictionally embracing an enclosed rod, a member engaged `by said, spring body and adapted to be connected bythe latter tovan embraced rod, and a device on the member for exerting an unwinding spring body for enlarging the normal diameter of the body and thereby loosening the grip or' the body on the embraced rod.

In testimony whereof I affix my signature.

ROYAL A. LETT.

force on the coils of the 

